We examined the relationship among handedness, fraternal birth order, and sexual orientation in men and women from China, and analyzed the influences of the components used to assess sexual orientation and the criteria used to classify individuals as homosexual on this relationship. A total of 395 heterosexual men, 189 non-exclusively homosexual men, 289 exclusively homosexual men, 544 heterosexual women, 142 non-exclusively women, and 299 exclusively homosexual women took part in a web-based survey. Our results showed that exclusively homosexual women are more likely to be non-right-handedness than heterosexual women, whereas only non-exclusively women are more likely to be non-right-handedness than heterosexual women when sexual orientation was assessed via sexual identity and sexual attraction, and only non-exclusively men are more likely to be non-right-handedness than heterosexual men when sexual orientation was assessed via sexual attraction. All men had a significantly late position in the birth order of the children in their families and had a significant excess of older sisters, but not older brothers. We concluded that the male-preference stopping rule adopted by Chinese parents affected birth order and sibling sex ratio in relation to sexual orientation. After controlling the male-preference stopping rule, we still did not find the fraternal birth order effect and the interaction of sibling sex ratio, handedness and sexual orientation. We concluded that the relative small sibling size may be one of the reasons why we could not replicate the fraternal birth order effect in Chinese population. This study contributes to the current understanding of the relationship among handedness, fraternal birth order, and sexual orientation

The Journal of Sex Research是Society for the Scientific Study of Sexuality (SSSS)的官方期刊，2014年影响因子2.695，社会科学交叉学期排名第一，是性与性别研究领域的重要期刊。